Control valve for reversible refrigerating systems



Nov. 10, 1964 w. o. LUM 3,156,250

CONTROL VALVE FOR REVERSIBLE REFRIGERATING SYSTEMS Original Filed Nov. 29, 1955 INVENT OR WALTER 0. LUM

ATTORNEYS United States Patent 3,156,250 CONTROL VALVE FOR REVERSIBLE REFRIGERATING SYSTEMS Walter 0. Luna, 7 Crescent Road, Livingston, NJ. Original application Nov. 29, 1955, Ser. No. 549,705. Divided and this application Nov. 7, 1960, Ser. No.

4 Claims. (Cl. 137-113) This invention relates to controls for reversible refrigerating systems and particularly to an improved automatic two-way check, three-way valve for such systems.

This application constitutes a division of co-pending application Serial No. 549,705, filed November 29, 1955.

In recent years substantial applications have been found for reverse cycle refrigerating systems which are commonly called heat pumps. These systems are frequently made to be reversible so that they may be employed for cooling in the summer as well as for heating in the winter.

The reversing of a heat pump circuit requires that the functions of the heat exchange units to be interchanged, the heating unit becoming the cooling unit and vice versa. In installations where reversing is accomplished by reversing the paths of the refrigerant in a compressor type refrigerating system an arrangement of selective valves must be provided in the refrigerant lines. Selectively operated valves may be employed for initiating the reversing operation and automatic check valves may be provided for completing the operation. Various arrangements of the control valves have been provided heretofore, many of which have been complicated in construction or have required complication of the remainder of the refrigerating system and thus have not proved entirely satisfactory for all applications. Accordingly, it is an object of the present invention to provide an improved automatic control valve for reversible refrigerating systems and the like.

It is another object of this invention to provide an improved two-Way check, three-way valve for refrigerating systems.

Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Briefly, in carrying out the objects of this invention, a two-way check, three-way valve assembly is provided for incorporation in a reversible refrigerating system of the type having two heat transfer units arranged to act alternatively as the evaporator and condenser of the refrigerating circuit. Selectively controllable valves are provided for determining which of the heat transfer units shall be connected to receive hot compressed refrigerant from the compressor and which shall be connected to act as the evaporator returning thevaporized refrigerant to the compressor intake. The two-way check, three-way valve is arranged to be connected either in the suction or discharge line of the compressor and operates automatically to complete the required connection as initially se looted by operation of the main control valves. The check valve assembly includes two valve elements constructed so that they are interlocked and close their respective ports or conduits alternatively. These check valves are further constructed to minimize vibration or chattering during their operation and to provide a simple and positive automatic actuation upon operation of the selective valves.

For a better understanding of the invention reference may be had to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of areversible refrigcrating system embodying the invention; and

FIG. 2 is an enlarged sectional view of a two-way check, three-way valve employed in the system of FIG. 1.

Referring now to the drawing, the reversible refrigeration system shown in FIG. 1 comprises two heat transfer coils 10a and 11a connected in a closed refrigerant circuit with an electric motor driven compressor 12a. The adjacent ends of the coils 10a and 11a are connected by a suitable expansion valve or differential pressure device illustrated by way of example as a flow restrictor or capillary tube 13a and the other ends of the coils ltla and 11a are connected to conduits 21a and 22a and may either receive or discharge refrigerant through these conduits depending upon the positions of two alternatively actuated control valves 136 and 137 and a twoway check, three-way valve 138 which are arranged in the discharge connection of the compressor 12a. The two-way check, three-way valve 138 is connected in the suction line of the compressor 12a. The valve 136 is actuated by a solenoid coil 140 and the valve 137 by a solenoid coil 141.

During the operation of the system shown in FIG. 1, when there is a demand for cooling, the bi-metallic element 27a moves to the left to engage its left hand contact and energizes the coil 36a, thereby closing the switch 41a and starting the compressor by closing of the power switch 46a. The circuit for the solenoid coil 141 is energized through the line 42a, the switch blade 50a in its right hand position, a line 142, the coil 141 and the return line 54a. This energizes the solenoid coil 141 and opens the valve 137, as indicated on the drawing, whereupon refrigerant is discharged through the valve 137 and flows to the outdoor heat transfer coil 11a. Here the refrigerant is cooled and liquefied and then flows through the capillary tube 13a to the indoor heat transfer coil 10a where it is vaporized by the absorption of heat from the air within the enclosure to be conditioned, the vaporized refrigerant being returned to the compressor through the left hand port of the valve 138 and a suction line 143. Upon a change in the temperature conditions in the zone being conditioned and a movement of the bi-metal element 27a to the right to engage contact 55a, the coil 56a is energized; the armature 57a is then lifted to shift the position of the control switch 33a by rocking the member 48a counterclockwise about its position and also closing the switch 58a to start the motor. Engagement of the switch 33a with its left hand contact closes a circuit in the line 42a through a lead 144 to the coil 149, thereby opening the valve 136. The valve 137 now closes, its solenoid coil 141 having been de-energized by operation of the switch 33a, and there is a pressure equalizing connection between the two sides of the system through the two valves 136 and 137. Hot compressed refrigerant is now supplied to the indoor heat transfer coil 10a through the valve 136 and the valve 138 shifts to the right. The liquefied refrigerant flows through the capillary 13a to the heat transfer coil 11:: where it is vaporized by the absorption of heat from the outdoor air and is returned to the compressor through the right hand port of the two way valve 138.

In the event that during the operation of the heat trans fer coil 10a as a heating coil in the manner just described, the coil 11a becomes coated with a layer of frost of sulficient thickness the defrosting control a will operate to shift the switch 37a to its left hand position in engagement with its contact 67a and will thereby switch the control from the coil 56a to the coil 36a and reverse the system, de-energizing the coil and energizing the coil 141 so that the positions of the valves 136 and 137 are reversed. During this operation, the open passage through the valves 136 and 137 will afford unloading of the compressor by equalizing the pressure on the two sides of the system before the valve 136 has closed.

The structural details of the valve 138 are shown in FIG. 2. As shown in this figure the valve 133 comprises a cylindrical body 146 divided into a central chamber 147 and then chambers 148 and 1 .9 by two partition members 150 and 151 in which are formed the valve ports 152 and 153. The partition members 150 and 151 are secured in spaced relationship within the cylinder 146 by cylindrical spacing members 155, 156 and 157, and the entire assembly is held together by end plates 158 and 159. The inlet connections 23a and 24a are soldered, welded or otherwise suitably secured in openings in the end plates 158 and 159, respectively. The valve assembly comprises two valve discs, 161 and 162, mounted on a valve stem or bar 163 and arranged in the chambers 148 and 149 to close the valve ports 152 and 153 upon movement from the respective chambers toward the central chamber 147. Upon a change in the pressure differentials in the system, the one of the valves 161 and 162 closes which is on the side of the system connected to the higher pressure coil. In FIG. 2 the valve 161 is shown closed. The valve assembly including the stem 163 and the valves 161 and 162 is held in position and guided in its movement in the cylinder 146 by a pair of spiders 164 and 165 which are urged toward the valves 161 and 162, respectively, by springs 166 and 167. The springs 166 and 167 are retained between the spiders and the ends of the valve stem 163 by flanged washers 168 and 169 which are secured to the stem 163 near the ends thereof. In FIG. 2 the valve disc 161 is shown in engagement with the seat in the partition member 150 and the spider 164 is in engagement with the outer periphery thereof. In this position the spider 164 has been pressed away from engagement with disc 161 which has been forced by the difference in pressure between the inlet 23a and the chamber 147 into engagement with the seat in partition 150 closing port 152 and compressing spring 166. It will thus be apparent when the pressure in 143 is reduced spring 166 will act to move the valve 161 away from its seat on the partition member 150.

In order to prevent chattering due to the pulsations of the compressor, a damping device is provided which comprises a weight 170 slidably mounted on the central portion of the valve stem 163. The clearance between the weight and the valve stem is of the same order as that of the spider sleeves on the valve stem of FIG. 2 and thus any tendency of the valve stem to move will provide a damping action due to the film of oil between the weight and the stem and the inertia effect of the weight.

It will readily be apparent from FIGS. 1 and 2 that whenever the solenoid valves 136 and 137 me shifted to direct high pressure refrigerant to a different end of the valve 138, the valve will quickly close and is positive in action.

From the foregoing, it is apparent that the improved two-way check, three-way valves of this invention make possible a simple, reliable and positively acting reversing 4 control for refrigerating systems; the valves are of simple construction and require a minimum of service and attention during the operation of the refrigerating system in which they are installed.

While the invention has been described in connection with specific structural features, various modifications and other applications will occur to those skilled in the art, therefore it is not desired that the invention be limited to the particular construction illustrated and described and it is intended by the appended claims to cover all modifications which fall within the spirit and scene of the invention.

I claim:

1. A two-way check, three-way valve for fluid control systems comprising a hollow cylindrical valve body having a pair of spaced partition elements having ports therein and dividing the interior of said body into three zones, three external fluid connections for said body one communication with the central one of said zones between said elements and the others with the respective zones on the outer sides of said elements, a double headed valve member, guide means mounting said member for reciprocating movement with respect to said ports, said heads being spaced on said member to engage their respective ports alternatively, said guide means including a pair of positioning slides mounted on said valve member for relative movement axially with respect to said heads and springs for biasing said slides to positions at a predetermined fixed spacing, stop means in said body for engaging the respective one of said slides when the adjacent head approaches its respective valve port whereby upon closing of the port the respective spring is stressed to bias the valve head away from its port and damping means engaging said valve member for minimizing vibration thereof during movement of said valve member.

2. A two-way check, three-way valve for fluid control systems according to claim 1 wherein said damping means comprises a weight slidably mounted on said member between said heads and arranged to hold a film of oil between the weight and the member.

3. A two-way check, three-way valve for fluid control systems according to claim 1 wherein the portion of said member between said heads is of substantial size and weight and said slides are sufficiently loose to retain a film of oil between them and said portion to provide a vibration damping action.

4. A two-way check, three-way valve for fluid control systems according to claim 1 wherein said slides comprise spiders slidably mounted on said members and having arms slidably engaging the inner wall of said body.

References Cited in the file of this patent UNITED STATES PATENTS 1,588,657 Christenson June 15, 1926 

1. A TWO-WAY CHECK, THREE-WAY VALVE FOR FLUID CONTROL SYSTEMS COMPRISING A HOLLOW CYLINDRICAL VALVE BODY HAVING A PAIR OF SPACED PARTITION ELEMENTS HAVING PORTS THEREIN AND DIVIDING THE INTERIOR OF SAID BODY INTO THREE ZONES, THREE EXTERNAL FLUID CONNECTIONS FOR SAID BODY ONE COMMUNICATION WITH THE CENTRAL ONE OF SAID ZONES BETWEEN SAID ELEMENTS AND THE OTHERS WITH THE RESPECTIVE ZONES ON THE OUTER SIDES OF SAID ELEMENTS, A DOUBLE HEADED VALVE MEMBER, GUIDE MEANS MOUNTING SAID MEMBER FOR RECIPROCATING MOVEMENT WITH RESPECT TO SAID PORTS, SAID HEADS BEING SPACED ON SAID MEMBER TO ENGAGE THEIR RESPECTIVE PORTS ALTERNATIVELY, SAID GUIDE MEANS INCLUDING A PAIR OF POSITIONING SLIDES MOUNTED ON SAID VALVE MEMBER FOR RELATIVE MOVEMENT AXIALLY WITH RESPECT TO SAID HEADS AND SPRINGS FOR BIASING SAID SLIDES TO POSITIONS AT A PREDETERMINED FIXED SPACING, STOP MEANS IN SAID BODY FOR 